Pneumatic tire



June 28, 1960 J. SNELL PNEUMATIC TIRE:

Filed Dec. l5. 1958 INVENTOR States 6 Claims. (Cl. 152-341) This invention relates to a novel construction of pneumatic vehicle tire and more particularly to a tire formed of two annular intertting sections which are detachably connected together, and including an outer section which is provided with the tread surface of the tire and which may be removed and replaced when the tread becomes worn.

Another object of the invention is to provide such a tire wherein the replaceable outer section of the tire is capable of being quickly attached to or detached from the inner body section of the tire so that said outer section can be replaced without the necessity of scraping, cutting, sanding, gluing or vulcani/ing, as is normally required in retreading or recapping a pneumatic tire and which nearly always results in the retreaded or recapped tire -being badly unbalanced.

Still a further object of the invention is to provide a pneumatic tire wherein the two tire sections form separate air chambers which cooperate to maintain the tire sections assembled when the air chambers are inated, and wherein the air chamber of the replaceable outer section communicates by a restricted passage with the air chamber of the inner section to prevent rapid deilation of the tire due to puncturing of either air chamber.

Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawing, illustrating a presently preferred embodiment thereof, and wherein:

Figure l is a side elevational view partly broken away of the pneumatic tire;

Figure 2 is an enlarged fragmentary radial sectional view, taken substantially along a plane as indicated by the line 2 2 of Figure 1, and

Figure 3 is an enlarged fragmentary sectional view, taken substantially along a plane as indicated by the line 3 3 of Figure 2.

Referring more specifically to the drawing, the pneumatic tire in its entirety is designated generally 5 and includes an inner main bodyor casing section 6 and a replaceable outer tread section 7.

The inner or casing section 6 -includes the usual side walls 8 and 9 having beaded inner edges 10, as is conventional. In lieu of the outer tread surface, as is conventional in a pneumatic tire, the inner casing Section 6 is provided with a deep annular groove 11 formed in the periphery thereof. The inner part of the annular groove 11 is formed by an annular portion 12 of the casing section 6, which projects inwardly with respect to said casing section and into the outer part of the air chamber 13 thereof. Said inwardly extending casing portion 12 is provided with an opening 14 which is lined by a cylindrical portion 13 of a rigid grommet 15. The part of the annular portion 12, surrounding the opening 14, is clamped between the end flanges 16, to prevent expansion of said opening 14. The bore i7 of said cylindrical grommet portion 18, as seen in Figure 3, communicates with the groove 11 and the air chamber 13.

arent The outer tread section 7 comprises an `annular tube 19 forming an annular air chamber 20.- The tube 19, like the inner casing section 6, is formed of rubber, either natural or synthetic, and the outer portion of the tube 19 is substantially thickened to provide a tread portion 21, the outer surface 22 of which may be suitably grooved or cut to a considerable depth, as seen at 23, to provide traction means. The inner portion of the tube 19, at one point about the circumference thereof, is provided with an internally thickened wall portion 24 and an outwardly projecting nipple 25. The nipple 25 is disposed opposite the central part of the portion 24, as seen in Figure 3. The nipple 25 has a socket 26 opening outwardly of its distal end. A bore 27, of small cross sectional size, extends centrally through the wall portion 24 and into the nipple 25, and communicates with the'inner end of the socket 26.

As seen in Figure 3, the nipple 25 is of a Vlength-.to extend completely through the -bore 17 of the grommet and is of a diameter to have a snug fitting engagement therein. An elongated rigid hollow tube 28 has a restricted shank portion 29 which extends through the bore 27 and by which said bore is held expanded, so that the shank portion has snug fitting engagement therein. The tube 28 has an enlarged rounded inner end forming a head 30 which is disposed beyond the inner end of the bore 27 to resist outward displacement of the shank 29 through said bore. The tube 28 has an enlarged outer end 31, an inner part of which is disposed in the socket 26, The tube end 31 is of a diameter to maintain said socket expanded. The outer end of the tube portion 3l1 projects from the inner side ofthe grommet 15 into the air chamber 13- and is externally threaded, as seen at 32. A nut 33 is threadedly connected-to the tube portion 32 and has a flange 34 at its inner end which abuts against the grommet ange 16, which is disposed on the inner side of the wall portion 12, when said nut is tightened.

The tread section 7 is connected to or disconnected from the casing section 6 while the tire 5 is removed from a rim, not shown. After the nipple 25 has been forced inwardly through the grommet bore 17, the tube 28 isapplied by forcing the head 30 through the socket 26 and then inwardly through the bore 27 for expanding said bore and socket and so that the compressed wall of the nipple 25, disposed between the tube 28 and grommet cylinder 18, will effectively seal the grommet bore 17. When the nut 33 is thereafter applied, as previously described, the bore 17 will be effectively sealed so that no air can escape therethrough around the nipple 25. As previously described, the grommet 15 effectively seals the opening 14 to prevent any passage of air between said opening and the grommet. With the tread section 7 thus applied and connected to the casing section 6, the tire 5 is mounted in a conventional manner. The casing section 6 constitutes a tubeless-type tire, the chamber 13 of which is inflated in a conventional manner after the tire is mounted on a rim. As the chamber 13 is inated, a portion of the air escapes outwardly through a restricted passage, formed by the bore 35 of the tube,

has two separate air chambers 13 and 20. Accordingly,`

if'either chamber is punctured the tire will deflate slowly due to the fact that a part of the bore 35, extending" through the shank 29, will effectively restrict escape of air through the tube 28 into the punctured air chamber. Thus, a vehicle equipped with the tire 5 will have ample time to stop after either air chamberof the tire has been Y. not be punctured'and'before Vthe tire 5 can become deflated sufj ciently to adversely affect operation of the vehicle or tov j cause further damage to the tire.

Since the outer air chamber V20 is more susceptible to Vpuncturing,since` the tread portion 21'is disposed immediately around the Vouter side thereof, ,thev outer portion ofsaid-air chamber 20is preferablyprovided with a punc-` tureproof lining 36, ywhich is secured vagainst the kinner,

surface of-'the tread portion 21.

The casingV section 6 and'also'the tread' section 7 are provided with reinforcing means'37 of a typeV which is' conventional in connection with motor vehicle tires, as bestseen in Figure 2. The wall 9 is preferably provided with an'externally' thickened ring portion 38 to form a curb guard, or lboth sidewalls 8 and 9'may'be provided with such a curb guard, so that either side wall may provide the outer wall ofthe tire 5.

low nipple, and a rigid tube, forming apart of the stern, detachably mounted in and extending through said nipple and tube bore, said rigid Ytube having an externally threaded end extending into the first mentioned air chamber, and -a nut threadedly engaging said tube endV and bearing against saidgrommet Yand combining with theV rigidV tube and grommet to form said means for sealing said bore around the stern.

2. A pneumatic tire comprising a tubeless-type inner casing Ysection having'an `annular ai-r chamber, said casing sectionV having aV peripheral portion spaced outwardly from said air chamber and provided with a deep annular groove openingoutwardly thereof, said casing section having an annular wallY portion extending inwardly of -The peripheral 'edges -39Yof the casing sectionf 6 are feathered, as'seenin Figure 2, so that the exposed side edges 40- of the tread portion 21 form smooth uninter-Y rupted continuations of the curvature of the outer surfaces lof the sidewalls 8 and 9. Thus, the assembled tire 5 will Vappear to Vbe ofl one piececonstruction. 39 or" .the side wallsS and 9 are spaced inwardly suiciently from the tread surface 22 sothatjsaid side wall edges 39 will not be subjected to any wear.

vIt will lbe apparent that when the tire 5 is inflated that the inated chambers V13 and 20 will materially assist in maintaining the outer tread section 7 in close fit-ting engagement in the casing section v6.

The edges A When the treadjsection 7 has become wom, the tire 5 is Vremoved from its rim 'and the nut'33 'and tube 28 are thenV removed, after which the .treadV section 7 'can' be Y removed vfrom'the casing section 6 4and replaced Witha t. knew tread section 7. It Will also be apparent'that lthe Y new tread section 7 will not adversely aiect the balance -l of the tire 5.

' l. VA -pneumatic tire comprising from said airvchanrber and Vprovided with adeep annular Y groove'V opening outwardly'thereof, said 'casingwsection' having an annular wall portion extending inwardly of said chamber forming the bedrof said groove, said wall portionhaving a `bore' opening into 'the airchaniber Y and, groove; an outer tread section comprising an an- Lio . v Va tubeless-,type inner ,VT casingv sectionhaving an annular air chamber, said cas-V Y ing section having ,aY peripheral portion', spaced` outwardly said air chamber forming the bed of said groove, said wall portion having a bore opening intoV the air chamber and groove; an outer tread section comprising an annular tube fitting snugly in saidgroove and defining a second air chamber, said tube having a stem projecting through said bore into the first mentioned air chamber, Ymeans for sealing said bore around said stern, said stemlhaving a restricted ybore extending therethrough forming a restricted communicating passage between the air chambers, the peripheral portion of said tube being thickened to provide `a tread portion of substantial radial thickness extending outwardly from said groove and having an Vouter annular tread surface ofsubstantial width'and spaced radially outward from the outermostk peripheral portion of the casing section, a part of said stemV being formed integral with said tube and Vincluding a' nipple projectingoutwardly ifrom the tube and fitting in VSaid wall portion bore, said tube having a' restricted bore Y opening into Vsaid second air chamber and outwardly of the distal Vend of the nipple,rand a rigid tube detachably` mounted in and extending throughV said bore of the annnlar` -tube,rsaid rigid tube being of a size to expand the bore of the annular tube for compressing 'the nipple between -a partV of the rigid tube and the bore of Vthe wall portion for VYsealing said wall portion bore, whereby said rigid tube and nipple forniY said bore sealjngfmeans.

3, A pneumatic tire as iu claim 2, said rigid tube having a threaded end projecting intosaid first ,air chamberV and beyond the nipple andV grommet, anut threadedly engaging said threaded tube end and bearing against the inner side of said wall portion.

4. A pneumatic tire comprising anirinercasing section and an outer tread section, saidrcasingsectgion having an annular air chamber and la deep annular groove "opening outwardlyy'of ther periphery of thevcasing section, said casing section having an vannular wall portion separating saidair chamber and groove, said ,wall portion being 1nf wardlyibow'ed in cross section andgprotruding into'the air Y chambenrsaid tread section includingdranlannular tread nular tube fitting snugly in said groove and defining aV secundair chamber, said tube having astem projecting through said'bore into the rst mentioned air chamber,

means for sealing said bore'aroundsaid stern, said stern Y Y having arestricted bore extending therethrough formingV a V'restricted communicating passage` between thel air chambers, the'peripheral portion of said tubeV beingthick' cned to provide'a tread portion of'sub'stantial radial thickness'extending outwardly from said groove and havingY Van'outer annular tread surface of substantial Width andV spaced. radially outward from the outermost peripheral portion of the casingsection, said'wall portion of the casing section having `au opening, a grommetlining said opening and having a bore'f'orming the vbore of ,saidY walliportion, said stemincluding a nipple forming an in- 'Yteg'ralprojection of YsaidY tube, said nipple fitting detachably4 in the grommet bore, Vsaidturbe having va. 'j bore opening into the interiorthereofandinto saidhol `forming a sealed joint` between Vthe .rst mentioned Vair y portion of substantial width Zand thickness projecting outwardlyY from said groove and -anannular tube fformed integral with said tread portion and snuglytting the Ainner portion of'said :groove and defining a 'secondfair charnber, and meansextending'throlighlsaid wallY portion and chamber-and 'groove'and a Vrestricted'air'passage between ysaid .airchambers said wall portion havinga grommety provided with'a bore Vconnecting the tirst mentioned air chamber and groove, saidY means comprising a nipple forming a part ofthe tube and iitting sadrgromrnet bore, a passage formed Yin the .tube and'opening into the air Y chamber and outwardly of the distal end of said nipple,

and a rigid tube detachably mounted insaid passage for expanding the nipple in the vgromrnet bore toprovide said sealed joint between the Viirst mentioned air chamber'and groove, said rigid tube having `a bore forming said restricted air passage. Y'

5. YApneurnatic tire asin claim 4, said rigid tube havi ing an enlarged .inner end disposed internally of the annular tube and resisting removal of said rigid tube from the annular tube, said rigid mbe having a threaded en@ extending from the nipple and grommet into the lirst mentioned air chamber, a nut threadedly engaging said threaded tube end and bearing against the grommet to detachably secure the tread section to the casing section.

6. A pneumatic tire comprising an inner casing section and an outer tread section, said casing section having an annular air chamber 4and a deep annular groove opening outwardly of the periphery of the casing section, said casing section having an `annular Wall portion separating said air chamber and groove, said wall portion being inwardly bowed in cross section and protruding into the air chamber, said tread section including an annular tread portion of ysubstantial width and thickness projecting outwardly from said `groove and an annular tube formed integral with said tread portion and snugly tting the inner portion of said groove and defining a second air chamber, and means extending through said wall `portion and forming a sealed joint between the rst mentioned air chamber and `groove and a restricted air passage between said air chambers, said inner casing section having annular transversely spaced peripheral portions disposed outwardly of the annular -tube and between which an inner part of the tread portion is conined.

References Cited in the le of this patent UNTED STATES PATENTS 508,621 Kirk et al. Nov. 14, 1893 2,152,131 Benson et Ial Mar. 28, 1939 FOREIGN lATENTS 107,718 Austria Oct. 25, 1927 1,155,291 France Nov. 25, 1957 

